If the product is big enough I'll skim reddit. Nothing like hearing the hard facts from a pissed off anonymous hivemind that isn't going to let anyone off the hook. Even the apple subreddit has been crucifying the company as they keep falling down the stairs with every keyboard half-fix they silently release (I think we are at 'gen 4' now).
On the other hand there's certainly attempts at manipulating content on sites like reddit too for advertising purposes. Though I don't know if there are good statistics on how prevalent it is
